A printer includes a printing mechanism adapted to print characters or marks on a print medium such as paper located in the region of the printer adjacent to the print mechanism which is known as the print region. One known type of print mechanism includes at least one movable print element which is selectively moved towards the print medium in order to print marks on the print medium. Interposed between the print element and the print medium is a ribbon impregnated with ink and the ribbon is pressed into contact with the print medium by the print element in order that a mark in accordance with the shape of the print element may be printed on the print medium using the ink in the ribbon.
The ink ribbon is impregnated with ink of a desired color and composition and, as the printing operation continues, the ink is gradually transferred to the print medium. The ink ribbon is usually moved relative to the print mechanism so that different portions of the ribbon are used as the printing operation continues and the printer includes a ribbon feed mechanism to perform this ink ribbon movement. Eventually the ink in the ribbon becomes exhausted and the material of the ribbon becomes worn out and it is then necessary to replace the ribbon.
The ribbon, since it contains ink, is dirty for the operator to handle and therefore it is convenient to store the ribbon in a cartridge which can be inserted into and removed from the printer without the operator getting dirty hands. The cartridge will be connected to the ribbon feed mechanism so that the ribbon can be fed out of the cartridge, through the print region of the printer and back into the cartridge. The ribbon can be in the form of a continuous loop.
Since ribbons of different types can be used in the printer it is desirable to have some form of indication on the cartridge or on the ribbon itself of the type of the ribbon. If such an indication is visible it can be interpreted by the operator who can ensure that the correct ribbon is inserted into the printer. However with such an arrangement it may not be easy to see which type of ribbon is in a cartridge which is in the operating position in the printer. It is desirable for the printer itself to be able to detect which type of ribbon is in the operating position in order to be able to check whether instructions to print characters or marks in a certain color can be correctly interpreted by the printer.
In order to be able to print characters or marks in different colors without changing the ribbon in the printer it is known to use a ribbon which contains inks of different colors and compositions. For example the ribbon may be formed with a plurality of parallel stripes extending along the length of the ribbon, each stripe being separated from the adjacent stripes by some form of barrier and with a different ink composition being used to impregnate each of the stripes. In order to be able to place a stripe impregnated with a desired ink composition in the print region of the printer it will be necessary to be able to move the ribbon laterally of its length in addition to providing lengthwise movement by using the ribbon feed mechanism.
In order to provide this lateral movement it is known to support the cartridge about an axis extending parallel to the length of the portion of the multi colored ribbon in the print region and to pivot the ribbon cartridge about this axis. It is also known to feed the ribbon outside the cartridge along two arms which extend from the cartridge to opposite ends of the print region, in the direction of lengthwise movement of the ribbon, so that the portion of the ribbon between the arms extends through the print region. In order to provide lateral movement of the ribbon the arm can be pivotally attached to the frame of the printer and can be pivoted about the points of attachment. It is known to provide an indicator tab extending from an arm of this type which can be used to indicate the position of the arm.
It is also known to form a ribbon cartridge with an arm extending from and pivotally attached to the cartridge and to feed the ribbon from the cartridge along the arm to the print region of the printer and back into the cartridge. By pivoting the arm about its points of attachment to the cartridge the lateral position of the ribbon in the print region can be varied.
The object of the present invention is to provide a printer having a removable ink ribbon cartridge which can cooperate with a mechanism in the printer providing lateral movement of the portion of the ink ribbon in the print region of the printer and which has an indicator which cooperates with a sensing device in the printer so as to provide an indication of the transverse position of the portion of the ink ribbon in the print region, the type of ribbon in the cartridge and whether the cartridge has been correctly installed in the printer.
Another object of the invention is to provide a removable ink ribbon cartridge which can be used with a printer of this type.